Method and apparatus for assembling incandescent lamp mounts



l M.l L. STONE METHOD AND APPARATUS FOR ASSEMBLING June 21, 1949.

INCANDESGENT LAMP MOUNTS 5 Sheets-Sheet 1 Filed Aug. 14, 1947 e, 9, rm OIT V .TS o DLJ/ .T e L v mo A hw.

Y U A Ud b 1 M L. STONE METHOD AND APPARATUSFOR ASSEMBLING INCANDESCEN'I` LAMP MOUNTS lJune 2l `1949.

'5 Sheets-Sheet 2 Filed Aug. 14, 1947 lm/ervtov: Melvin L. Sfborje,

June 2l, 1949. M, L, STQNE 2,475,919

METHOD AND APPARATUS FOR ASSEMBLING INCANDESCENT LAMP MOUNTS Filed Aug. 14, 1947 5 Sheets-Sheet 3f lm/ervbor: Meh/in L. Selore,

June 21, 11949.

M.L.STONE METHOD AND APPARATUS FOR ASSEMBLING INCANDESCENT LAMP MOUNTS 5 Sheets-Sheet 4 Ftig.

. M.. L. STONE 2,473,919 METHOD AND APPARATUS FOR ASSEMBLING mcfmnsonm Lm mums June 21, 1949.

Filed Aug.' 14, 1947 5 SheetS-Sheei 5 Patented June 21, 1949 METHOD AND APPARATUS FOR ASSEM- BLING INCANDESCENT LAMP MOUNTS Melvin L. Stone, East Cleveland, Ohio, assigner to General Electric Company, a corporation of New York Application August 14, 1947, Serial No. 768,643

(Cl. 21S-4) 1i) Claims.

My invention relates in general to electric incandescent lamps and similar devices, and more particularly to method and apparatus for the manufacture and assembly of the mount thereof.

In certain types of high wattage incandescent lamps such as are used for projection purposes, for instance, and which employ a planar or segmental type filament comprising a plurality of coiled sections disposed in side-by-side relation, the filament is supported in place on the lead-in conductors of the lamp mount by means of a plurality of anchor wires which are hooked around the bights of the filament and which extend from upper and lower insulating bridge members mounted on the said conductors.

rIhe methods heretofore employed in the manufacture of that type lamp mounts have generally involved the application of various hand operations, such as the shaping of the segmental filament, its attachment to the lead-in conductors, and the bending of the filament anchor wires around the filament bights, which entailed a considerable amount of time, expense and inconvenience. In addition, such hand operations precluded the manufacture of a uniform finished product since the individual filament segments of each mount were not positioned in the same exact relation to one another and to the lead-in conductors and stem flare of the mount. Howe ever, the principal service (projection purposes) for which such type lamps are intended makes it highly desirable to have the filament and its individual sections positioned as accurately and uniformly as possible within the lamp in order to obtain the most efficient utilization of the light therefrom by the optical system of the apparatus with which the lamp is used.

It is one object of my invention therefore to provide an improved method of forming the mount structure of an electric incandescent lamp of the character described.

Another object of my invention is to provide apparatus for the manufacture of incandescent lamp mounts of the character described in accordance with the method comprising my invention.

Further objects and advantages of my invention will appear from the following detailed description of a species thereof and from the accompanying drawings in which:

Fig. 1 is an elevation, partly in section, of an electric incandescent lamp provided with a mount structure formed by the .method and apparatus comprising my invention; Figs. 2-5 inclusive are CTI detail views showing in elevation the stem, upper bridge, filament and lower bridge, respectively, of the lamp mount prior to their assembly in accordance with the invention; Figs. 6-8 inclusive are views illustrating the various steps in the manufacture of the bridge members shown in Figs. 3 and 5 prior to the formation of the hooks on the filament anchor wires thereof; Fig. 9 is a plan view of apparatus for forming the hooks on the filament anchor wires of the upper bridge; Fig. 10 is a section on the line IO-ID of Fig. 9; Figs. 11 and 12 are fragmentary sectional views of the apparatus of Figs. 9 and 10 showing the successive steps in the formation of the hooks on the filament anchor wires of the upper bridge; Fig. 13 is a fragmentary plan view of apparatus for forming the hooks and bending the fastening wires of the lower bridge, the view showing the first step in the hook forming and wire bending operation; Fig. 14 is a section on the line Illli of Fig. 13; Figs. 15 and 16 are fragmentary views, similar to Figs. 13 and 14 respectively, showing the second step in the formation of the hooks on the anchor wires of the lower bridge and the bending -of the end fastening wires thereof; Fig. 1'7 is an elevation, partly in section, of apparatus according to the invention for assembling electric incandescent lamp mounts of the character described; Fig. 18 is a plan View of the mount assembly jig and associated support means of the apparatus shown in Fig. 17 for assembling the lament and upper bridge of the mount with the stem thereof; Fig. 19 is a front elevation, partly in section on the line IS-IB of Fig. 18, of the assembly jig illustrated in Fig. 18; Fig. 20 is a transverse section on the line 2li-20 of Fig. 18, with the movable upper welding electrode shown in its lowered welding position; Fig. 21 is a plan View, similar t-o Fig. 18, of an assembly jig and associated support means according to the invention for assembling the lower bridge with the intermediate assembly' of the stem, upper bridge and filament formed by the apparatus of Figs. 17-20; Fig. 22 is an elevation, partly in section on the line 22-22 of Fig. 21, of the assembly jig illustrated in Fig. 21; and Fig. 23 is a transverse section on the line 23-23 of Fig. 21.

Referring to Fig. 1 of the drawings, the electric incandescent lamp there illustrated comprises a tubular glass bulb or envelope l having a base 2 secured to its neck end. Extending into the bulb longitudinally thereof from its neck end and sealed thereinto is a mount 3 according to the invention comprising a stem 4, upper bridge 5, filament 6, and lower bridge 1, shown in detail in Figs. 2 5, respectively. The stem 4 comprises a glass stem tube portion 8 having an outturned flange or flare 9 at one end and a press portion I0 at its other end through which are sealed a pair of rigid lead-in conductors or wires II-I I. The stem 4 is also provided with a glass exhaust tube I2 extending through the stem tube 8 and fused at one end into the press portion I0 of the stem tube. The exhaust tube I2 communicates with the interior space of the bulb l through an opening I3 in the press portion I0 of the stem tube. After the mount 3 is sealed into the bulb by fusion of the stem tube ange 9 to the bulb neck, the bulb is exhausted and gas lled through the exhaust tube I2 and the latter then tipped or sealed off in the usual manner.

The lead-in conductors II-I I, which are connected at their outer ends to the terminals of the base 2, extend into the bulb longitudinally thereof from the stem press I0 in parallel relation to each other. inwardly of the bulb the said conductors I I-I I, in the particular form of lamp shown, are laterally bent outwardly away from eachother to form parallel extending off-set or side portions IIIe-I4 between which the filament 6 is mounted. At their innermost ends, the lead-in conductors I I I I are bent inwardly towards one another to forni inturned portions I5-.I 5 to which the filament 6 is connected.

The iilament 6 is of the high-wattage planar type comprising a plurality of parallel coiled segments IS of tungsten wire disposed in sideby-side relation and joined by upper and lower uncoiled or bight portions I1, I1', respectively. For the purposes of the invention, the filament 6 should be accurately formed to shape so as to locate the upper bights II as well as the lower bights II and the individual coil segments I6 of each filament in substantially the same exact relation to each other. For such reason, I have found it especially desirable to employ mechanically formed filaments 6 as made by the apparatus disclosed and claimed in copending U. S. application Serial No. 686,656, Isaac et al., led July 27, i946, and assigned to the assignee of the present invention, now Patent No. 2,449,653, dated September 21, 1948. The particular filament 6 illustrated is of the biplane type having alternate segments I6 staggered so as to lie alternately in two parallel planes. However, the invention is applicable as well to the mounting of other types of filaments, such as monoplane type filaments which have their individual coiled segments lying in a single plane only. The Opposite ends of the filament E are provided with coiled end portions or segments I8-I8 which are electrically connected to the inturned end portions I5-I5 of the conductors II-II by screw-threaded spuds or insert plugs I9-I9 which are screwed at one end into the filament end coils I8I8 and have tight frictional engagement therewith. The other ends of the spuds I9-I9 are welded to the inturned inner end portions I5-I5 of the lead-in conductors. In the particular form of lament illustrated, the spuds I9-I9 extend more or less upwardly away from the lainent and diverge at a slight angle. For the purposes of the appended claims, the spuds IS-IS together with the filament end coils I8-I 8 into which they are screwed may be considered as constituting the end connection portions of the iilament itself.

The planar filament 6 is disposed in the plane, more or less, of the side portions I4 of the lead-in conductors, and it is supported in place by means of the upper and lower bridges, 5 and 'I, respectively. The said bridges 5 and 1 are each comprised of short insulator members 20 or 20' of suitable insulating material, such as a short length of glass rod for instance, having a plurality of filament anchor wires 2I or 2| and end support or fastening wires 22 or 22 extending in parallel relation therefrom and suitably secured thereto, as by embedding therein. The anchor wires 2I and 2I of the bridges 5 and 'I are formed at their ends with hooks 23 and 23', respectively, which are hooked around the bights I'I, I'I of the filament E to thereby support the same in place. The upper bridge 5 is mounted on the lead-in conductors I I in a transversely extending position overlying the inturned conductor ends I5 with the anchor wires 2I extending down between and in the plane of the said conductors, and it is fastened in place by welding its end support wires 22 to the said inturned ends I5 of the lead-in conductors. The lower bridge 'I is mounted on the lead-in conductors II in a transversely extending position beneath the filament 6 and between the offset side portions I4 of the said conductors with the anchor wires 2| extending upwardly in the plane of the lead-in conductors, and it is fastened in place by welding its end support wires 22 to the said side portions I4 of the lead-in conductors.

In accordance with the invention, the upper and lower bridges 5 and 'I are accurately preformed to uniform final shape or form (Figs. 3 and 5) ready for assembly with the stem 4 and filament 6. For this purpose, the said bridges 5 and 'I are jig-formed in a manner that assures their uniformity of construction. Figs. 6-8 illusstrate the procedure employed for embedding the anchor wires 2l and the end fastening wires 22 in predetermined position within the glass rod 20 of the upper bridge 5, a similar procedure being also followed for the lower bridge '1. As shown in Figs. 6-8, the anchor wires 2I and end fastening wires 22 are iirst inserted or dropped into retaining apertures 24 in a stationary holder block 25, the said wires being held by the block in pref determined parallel relation with one another with their upper ends projecting upwardly a predetermined distance from the holder block. A glass rod 20 is then supported at its ends in recessed seats 26 provided therefor in the inturned spaced arms 21 of a vertically reciprocal slide or carrier 28, the glass rod 20 being supported on the slide in a horizontal position overlying and in the plane of the said wires 2| and 22. In the particular case illustrated, the slide 28 is slidably mounted on the holder block 25 for vertical movement thereon, and it is spring held in the elevated position shown in Figs. 6 and 7 by suitable spring means (not shown). With the wires 2I, 22 and the glass rod 28 thus held in the block 25 and slide 28, the glass rod 20 is heated to a softened condition by gas res 29 from burners 30 located on opposite sides of the slide, whereupon the glass rod 2 8 and its supporting slide 28 are pushed or moved downwardly by a depresser member 3| engaging the glass rod, against the resistance of the spring means acting on the slide, to thereby force the softened glass rod down onto the upper ends of the wires 2I and 22 so as to cause the said wires. to be embedded to a predetermined depth in the glass rod. Upon cooling and solidication of the glass rod 20, the depressor member 3| is raised and the glass rod with the wires 2|, 22 embedded therein is removed from the carrier slide 28.

The free ends of the anchor wires 2I, 2lv of the respective bridge members 5 and 'I are then bent to provide accurately formed hooks 23, 23 thereon. In accordance with the invention the hooks 23, 23 are formed by suitable hook-forming devices, such as shown in Figs. 9-16, which assurethe uniformity in the shape and positioning of the hooks. The hook-forming device 32 for the upper bridge 5 is shown in Figs. 9-12 and it comprises a holder 33 on which the bridge 5 is rested in a horizontal position, with its unformed anchor wires 2| extending horizontally and resting in parallel aligning grooves 34 formed in the horizontal upper surface 35 of the anvil portion 355 of the holder. The said holder 33 is mounted on a base member 3l, and it is provided with a transversely extending channel-way or positioning recess 38 for receiving the glass rod 20 of the bridge 5 to position the latter in a predetermined position in the holder with the free ends of the anchor wires 2| projecting a predetermined distance, as indicated at 33, beyond a forming lip or finger on the holder anvil position 36, around which lip the said wires 2| are bent to yform the hooks 23. Extending upwardly through the base 31 at a point directly beneath the forming lip 40 of the anvil 36 is a tube 4| which is connected at its lower end to a supply of heated air or other gaseous medium under pressure for the purpose of directing a stream of the heated air or gas against the lip 40 and the projecting portions 39 of the bridge anchor wires and thereby prevent their breakage during the bending thereof. The projecting ends 39 of the bridge anchor wires 2| are bent around the forming lip 40 by a slide assembly 42 comprising a lower or main slide 43 and an upper or sub-slide 44, which assembly 42 is slidably mounted in a guide block 45 for horizontal reciprocating movement therein in a direction towards and away from the anvil 35 of the bridge holder 33. The guide block 45 is secured to the base 3l of the forming device, and it is provided with an upwardly facing guide way or channel way 46 within which the slide assembly 42 is guided and retained by a cover or retaining plate :il fastened to the ways 46. The upper slide 44 rests on top the flat upper surface 48 of the lower slide 43, which surface 48 is horizontally aligned with the flat under surface or face 49 of the forming lip 40 on the anvil 36 in a manner such as to pass underneath and slide across the said lip underface 49, with a very slight clearance therebetween, when the slide assembly 42 is moved forwardly towards the anvil into its hook forming position. The two slides 43 and 44 are also slidable relative to each other in the direction of the sliding movement of the slide assembly itself, and the upper slide 44 is normally held in an advanced position relative to the lower slide 43, when the slide assembly is in its retracted position as shown in Figs. 9 and 10, by the pull of a tension coil spring 50 fastened at one end to a post 5| upstand ing from the upper slide 44 at a point spaced from the rear end of the retaining plate 41. The other end of the spring 56 is fastened to a similar post 52 upstanding from the lower slide 43, and projecting through slots 53 and 54 in the upper slide 44 and retaining plate 41, respectively.

At its forward end, the under surface 55 of the upper slide 44 is under-cut, as shown at 56, for a distance corresponding more or less to the length of the upper anvil surface 35 and to a depth corresponding to the thickness of the forming lip 40 on the anvil, to thereby align the undercut surface 56 with, and permit it to pass or slide over the saidanvil surface 35with a very slight clearance therebetween, when the slide assembly 42 is advanced to its hook-forming position. The under-cut portion 56 of the upper slide terminates in a transversely extending shoulder 51 which tapers downwardly and rearwardly at an angle, for instance 45 or thereabouts, to the horizontal. The forward end of the lower slide 43 is also tapered and beveled downwardly and rearwardly, as indicated at 58, at an angle corresponding more or less to the taper of the shoulder 5l on the upper slide, and it is provided with grooves 59 which are longitudinally aligned with the grooves 34 in the anvil 36 and which are adapted to receive the projecting ends 39 of the bridge anchor wires 2| after they have been bent down at an angle by the tapered shoulder 51' on the upper slide. The said grooves 53 are continued around the rounded upper corner 63 of the slide 43 and back over the upper surface 48 thereof, as indicated at 3 i, to receive and continuously guide the bent or hooked ends of the bridge anchor wires 2| (Fig. l2) as they are being bent to final hook shape by the said slide 43.

In the operation of the hook forming device 32, the bridge 5 with its unformed anchor wires 2| is first positioned in the holder 33 after which the slide assembly 42 is advanced towards the anvil 35 by swinging movement of a hand lever |52 pivotally mounted at one end on the base -31 and connected by a link 33 to the lower slide 43. As the lower slide 43 is moved forwardly by the hand lever 52, the upper slide 44 is carried along therewith by the pull of the coil spring 5|). During the advance movement of the slide assembly 42, the forward end of the upper slide 44 first passes over the upper surface 35 of the anvil 36, thus trapping the bridge anchor wires 2| in the grooves 34 in the said anvil surface 35 and so locking the bridge 5 rmly in place on the holder 33. Further forward movement of the slide assembly 42 to its forwardmost position shown in Fig. 11 causes the tapered shoulder 5'! on the underside of the upper slide to engage the projecting ends 38 of the anchor wires and bend them down at an angle over the end of the forming lip 4@ on the anvil `36. Upon further forward Inovement of the lower slide 43 relative to the upper slide v44 (the latter being restrained from such further forward movement by the engagement of the shoulder 5'! with the anchor wires 2| bent around the lip 43), the down-bent ends of the said wires 2| are engaged by the tapered forward end cf the lower slide 43 within the guide grooves 59 therein and are bent around the forming lip 40 into their final hook shape, in the manner shown in Fig. 12.

The hook forming device 64 (Figs. i3-i6) for the lower Ibridge l is similar to that employed for the upper bridge 5 except that the bridge holder 33 and the lower and upper slides 43 and 44 are provided with additional cooperating means for engaging and bending the end fastening wires 22 of the bridge laterally outward. For this purpose, the holder 33 is provided with side anvil portions 65 disposed outwardly of and extending upwardly alongside and above each of the bridge fastening wires 22 when the bridge l is positioned in place in the holder. The said side anvil positions 65 are formed with front anvil surfaces 66 facing the slide assembly 42 and extending laterally at an angle corresponding substantially to the angle at which the fastening wires 22 are to be ultimately bent. In the particular case illustrated, the anvil surfaces 66 taper outwardly and back at a slight angle. The upper slide 44 is made of a width slightly greater than the space between theinsidev or facing sides 61 ofr the side anvil positions 85 sov as to engage the bridge fastening wires 22' upon forward movement of the slide. At its forward end, the upper slide 44' is formed with verticallyextending beveled forming surfaces 68 at each side thereof which taper back at an angle of about 45 0r so and are provided with grooves 69 horizontally aligned with and adapted to receive and guide the end fastening wiresv 22 of the bridge 1 on the holder 33'. The lower slide 43! is provided with upstanding side extensions 10 which extend. upwardly on each side of the upper slide 44' and slide along the side faces 1|: thereof. The forward ends of these side extensions 10. are formed with inner and outer forming surfaces 12 and 13 respectively, for engaging and bending the bridge fasteningwires 22 to final shape. The inner forming surfaces 12 oppose the tapered anvil surfaces 66 on. the side anvil portions 65, and they extend approximately parallel to the said surface 66. The outer forming surfaces 13 taper outwardly and back at an. angle of about 45 or so. The forming surfaces 12 and 13 are also provided with grooves 14 which are horizontally aligned with and are adapted to receive and guide the bridge fastening wires 22 during the bending thereof to final shape.

Upon advance movement of the upper slide 44, to its forwardmcst position as shown in Figs. 13' and 14', the projecting ends 39 of the bridge anchor wires 2| 40 as before while the end fastening wires 22 are engaged `by the beveled forming surfaces 68 and are bent laterally out at an angle corresponding to the bottom of the grooves 69 within which the said wires 22 are received and guided. Continued advance movement of the lower slide 43 to its forwardmcst position shown in Figs. 15 and 16 then bends the down-turned ends of the bridge anchor wires 2| to final hook shape as before, while the side forming surfaces 12 and 13 engage the out-turned ends of the fasteningv wires 22 and bend them backwardly against the tapering anvil surfaces 66, the wires 22 being continuously received and guided', during the bending thereof, in the guide grooves 14 and being finally clamped between the said anvil surfaces` 65 and the innermost forming surfaces 12y of the lower slide, as shown in Fig. 1'5.

The bridges 5 and 1, as pre-formed in the manner described above, are then assembled together with the filament 6 and stem 4 to form the fln ished lamp mount 3. In accordance with the invention, the assembly of each of the bridges with thev filament and stem is performed in a manner which assures the accurate and uniform mounting of each filament E on the stem in definite predetermined relation to the lead-in conductors I |v and to theange 9 on the stemtube 8. For this purpose, assembly jigs are employed for holding the Various parts in properly assembledA and positioned relation to each other while they are welded together on an electric resistance Welder (Fig. 1.7) of conventional type comprising a hollow support column 15 upstanding from a table or bench 16 and provided with a lower bracket 11 and a hollow upper bracket 1-8 which carry vertically extending opposed welding electrodes 19 and 80 relatively movable ina vertical direction towards and away from each other. The lower electrode 19 is held stationary on the lower bracket 1v1 while the upper electrode 80: is verticallyI reciprocal ony the. upper bracket 18:,.t being. carried by a, head 8| comprising a ver are bent down over the anvil lipV tically extending slide rod 82 which is slidably mounted in bearings 83' on the upper bracket 18 for vertical reciprocating movement therein. The slide rod' 82 with its associated electrode 80 is normally held in a raised or elevated position, as shown in Fig. 17, by the pull of a tension coil spring 84 located within the hollow interior of the upper bracket 18 and connected at one end tov a spring post 85 on the bracket and at its other endto one arm 86 of a three-armed lever 81 mounted at its hub on a horizontal shaft 88 which is rotatably supported within the bracket 18. A second arm 89 of the lever 81 is pivotally ccnnected to the slide rod 82 by a pin 90, while the thirdarm 92 of the lever is connected to a chain 92' which passes over and around a guide pulley or sheave 93 mounted within the bracket 18 and extends down through the hollow column 15 and through anopening (not shown) in the table 18 whereit is connected to one arm 94 of a foot lever or treadle 95 pivotally mounted beneath the table on a bracket 96fastened thereto. The other arm 91 of the treadle 95 is provided with a foot pedal 98- which, when depressed or moved backwardly, pulls down on the chain 92 which, acting through the three armed lever 81, then moves the slide rod 82' and its electrode 80 downwardly into weldingy position. The head 8| also carries a spring pressed hold-down pin 99 which is adapted to engage and hold, during the welding operation, the parts. of the mount to be welded together.

Mounted on the upper bracket 18 is a switch |00l for connecting the electrodes 19, 80 to a suitable source of power supply. The said switch |98 is provided. with an operating push-pin or plunger |0`| which is engaged by an adjustable screw |02 carried by an arm |03 mounted on the shaft 88. When the upper electrode 80 is lowered to its welding position, the arm |03A is swung upwardly by the rotation of shaft 88, causing the screw I 92 to engage and depress the switch plunger |9| and thus close the switch.

Mounted on the lower bracket 11 of the welding apparatus directly beneath the upper electrode 88 thereof is an assembly jig |04 for holding the stem 4, filament 6, and upper bridge 5 in predetermined assembled relation with each other and in proper' welding position. between the spaced electrodes 19 and 80. A different jig |05 (Figs. 21-23), mounted in a similar position on a similar welding apparatussuch. as sho-wn in Fig. 17, is employed to hold the lower bridge l'l in assembled welding relation with the Welded assembly of the stem 4, filament 6. and upper bridge 5 as formed in the jig |04.

'Ihev assembly jig. |04, shown in detail in Figs. 18-20, comprises an elongated base plate |09 mounted in a horizontal position on arms |01, |08, of suitableplastic or other insulating material, which extend from a holder cross bar |09 secured to the. lower bracket 11 of the welding apparatus. The base plate |08 is provided with a transverse slot ||\0. through which the stationary electrode 19 projects upwardly. On its upper side, the base plate |06 is provided with support means on which the stem 4, filament 8 and upper bridge 5 are rested and held in predetermined relation to each other, as shown. The stem 4 is supported in a horizontal position extending longitudinally of the base plate |06, with its side conductor portions |4 disposed in a horizontal plane immediately above the plane of the upper end of the stationary electrode 19, by means of spaced supports H2 and llspaced apart longitudinally of the base plate. Support ||2 comprises an L-shaped bar, one leg II4 of which is secured to the base plate |06 and the other leg II5 of which extends upwardly therefrom and is provided with a notch or recess I I6 in its upper end within which the exhaust tube I2 of the stem is received and supported. prises a block-shaped member upstanding from the base plate |06 and provided with upwardly opening guide slots I I'I in its upper surface within which the side portions I4 of the stem lead-in conductors are received and supported. The stem 4- is located in a denite position longitudinally of the base plate |06, with its in-turned conductor ends I5 overlying the cross slot I|0 in the base plate, by means oi an adjustable stop screw II8 on the support I I2 against the end of which the rim of the stem tube Iiange 9 is held by the operator during the welding operation, as shown in Fig. 19.

Mounted on the upper side of the base plate |06 alongside the block I I3 is a lament support block I|9 provided with a iiat upper surface |20 on which the filament 6 is adapted to be rested flat, to position it in the horizontal plane, more or less, of the stem conductor portions I4 with the diverging end connection or spud portions I of the lament extending towards and across the in-turned ends I of the stem lead-in conductors. The support block |I9 is provided with lugs |2I and |22 upstanding from the upper surface |20 thereof and having a series of aligned slots |23 and I 24 therein which correspond in number and spacing to the anchor wires 2| of the bridge 5 and extend longitudinally of the base plane I 06, within which slots the said anchor wires are received and supported to thereby horizontally position the bridge 5 in place relative to the stem conductor portions I4.

Pivotally mounted on the base plate |06, on that side of the cross slot IIO opposite to the bridge support block II3, is a lever |25 pivoted on a pin |26 and provided with an upstanding slotted finger |2'I adapted to project up between the anchor wires 2| of the bridge 5 and engage the side of the glass insulator rod 20 thereof facing the filament. A tension coil spring |23, connected between the lever |25 and a spring post |29 fastened to the base plate |06, exerts a constant pulling force on the lever tending to pivot it in a direction away from the bridge support block I I3. When the upper bridge 5 and filament 6 are rested in place in assembled position on the support blocks II3 and II9, with the anchor wires 2| of the bridge hooked to the upper bights II of the lament and the nger |21 of the lever |25 engaging behind the glass insulating rod 20 of the bridge, as shown in Figs. 18 and 19, the spring pivoted lever |25 then exerts a force on the bridge 5 acting to continuously pull it in a direction longitudinally of the base plate |00 and away from the block II3, thereby drawing the upper bights I1 of the filament tight against the vertical face |30 of the lug I 2| on the support block I 3 which thus serves to accurately locate the lament in predetermined longitudinal relation to the stem 4. In such position, the end connection portions I0 of the filament and the end fastening wires 22 of the upper bridge extend across and rest on the iii-turned conductor end portions I5 of the prepositioned stem 4.

To enable the selective positioning of the crossed portions of the lament, lead-in conductors and bridge fastening wires in proper Welding position between and in vertical alignment with The other stern support II3 comthe electrodes l0 and 80, the jig |04 is movabiy mounted on its support bracket 'I'I for movement laterally of the vertical path of travel of the upper electrode. For this purpose, the `base plate |06 of the jig is pivoted adjacent one end, on a pivot pin I3I upstanding from the support arm |01, so as to swing in a horizontal plane. Adjacent its other end, the base plate |06 is provided with an arcuate slot |32 having its center oi curvature coincident with the axis A of pivotal movement of the base plate on the pin ISS, through which slot extends a stop pin |33 upstanding from the support arm |08. The ends |30 of the slot |32 serve as stops against which the pin |33 strikes to limit the swinging movement of the base plate |06 in each direction and thus automatically position the jig in its limiting welding positions, i. e., the positions for effecting the outermost of the two welded connections which are to be made to each irl-turned conductor end I5.

After the positioning of the stem 4, filament Ii and upper bridge 5 in place on the jig ltd, the latter is then swung to its various welding positions wherein the crossed portions of the lament end connections I6, bridge wires 22 and conductor ends i5 are successively located. between. and in vertical alignment with the electrodes and with the iii-turned conductor ends iii resting on the upper end ||I of the stationary electrode iii. In each of the said welding positions of the jig |04 the upper electrode 00 is moved downwardly, by movement of the foot pedal tid, to successively clamp the crossed portions of the iilament end portions I3, bridge wires El? and conductor ends |`5 between the two eiectrodes and simultaneously weld them together.

IThe intermediate welded assembly |35 of the stem 4, filament 6 and upper bridge 5 thus formed on the rst jig |04 is then assembled together with the lower bridge "I in the second jig |315 (Figs. 21-23), and the said lower bridge 'I welded to the side conductor portions I4 of the stern to complete the mount structure 3. The jig |05 is similar to the previous jig |04 and comprises an elongated base plate |06 horizontally positioned on the insulating arms |01, |08 of the lower support bracket 'I'I of a welding apparatus similar to that shown in Fig. 17. The intermediate welded mount assembly |35 is held by supports Il?! and IIS in a horizontal position on the base plate, with the undersides of the side conductor portions I4 horizontally aligned with the upper end I I of the stationary lower electrode 79. Support I|2 is provided with a notch H6 within which the exhaust tube I2 of the mount assembly |35 is received and supported, and the other support II3 is provided with upwardly opening grooves I Ii within which the side conductor portions ifi of the stem are received and supported.

The intermediate welded assembly |35, with the anchor wires 2| of the lower bridge 'I hooked to the lower bights I1 of the lament 6 and the laterally bent portions |36 of the bridge fastening wires 22 resting across the side conductor portions I4, is then mounted in place on the supports |I2, |I3 with the slotted nger |21 of the spring pivoted lever |25 extending up between the two innermost bridge anchor wires 2| and engaging that side of the glass rod 20 of the lower bridge which faces the lament. A tension coil spring |28', connected between the lever |25 and a spring post |29', exerts a constant pulling force on the lever tending to pivot it in a direction away from the filament, thus drawing the "vll bridge anchor Wire hooks' 23' tight into the lower bights of the lamentand in turn pulling the nlament taut between the two support bridges and l. The spring |28' employed is of relatively soft acting character so as not to cause undue stretching or elongation ofthe filament segments IS. Engagement of the rim ofthe stem tube fiange 9 with the upturned-leg |-|5'-of the support H2 restrains movement of the mount assembly |35 longitudinallyof the jig |05 under the influence of the pulling force exertedthereon by the spring actuated lever |25.

As in the case of thejig |04, the base plate I 06 of jig |05 ismovably mounted on its support arms |01, |08 for movement llaterally of the path of travel of the upperelectrode 00 to enable the positioning of the rjigrin each of its two welding positions wherein the crossed portions of the side conductor portions |4 and the bridge fastening wires 22' are located between and in vertical alignment with the electrodes. As before, the base plate |06 is pivoted atr one end of the pivot pin |3| while its other end isformedwith an arcuate guide slot |32'.- into Ywhich .the pin |33 extends. The slot |32', however, lis made of much shorter radius thanthat of theslot v| 32 in jig |04 while the pivot pin .|3I rides in a longitudinally extending slot |31. in the base plate |06 so as to impart tothe jig a combination swinging and linear movement such as -Will prevent the lower electrode 'I9 from` striking against the glass rod of the lower bridge 'l when the jig is shifted from one of its welding positions to the other thereof.

With the intermediate Weldedmount assembly |35 and the lowery bridge 1, positioned and held in assembled relation, as ydescribed on the jig |05, the latter is then successively shifted into each of its welding positions (as determined by the engagement of the stop pin |33 with the ends |34 of the arcuate slot |32). and the lupper electrode B0 moved downin each of lthe said welding positions, to cause it to engage. andweld the bridge fastening wires 22 to the side conductor portions i4 of the stem, thus completing the assembly of the mount 3 according to the invention, ready for sealing into the envelope of the lamp. The back weld (i. e., the one indicated in Fig. 21), is preferably made rst so that the hold-down pin |38 will engage the anchor wir.es.2|, of the lower bridge l, as shown in dash-dot lines, to thereby position and hold them in a, horizontally extending position during the welding operation.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In the manufacture. of amount for an electric incandescent lampof the' type having a seg- .mental filament supported' by a bridge member fastened to the lead-in; conductors of the lamp, the step of welding; the lament and the support bridge to the lead-in conductors whilejigheld in predetermined assembled relation with each other.

2. The method of mounting anincandescent lamp lament in place on the lead-in-conductors and support bridges of the lamp mount which method comprises, successively jig-'positioning the filament and lead-inv conductors together in predetermined assembled relation with each of the support bridges, and welding thexlament and the support bridges togthe said lead-in conductors while thus jig-held inpredetermined interrelation.

3. The method of vmounting an incandescent lamp filament in place onA thelead-in conductors .and upper and lower support bridges of the lamp mount which method comprises, jig-positioning the filament and lead-in conductors together in predetermined assembled relation with one of said support bridges, Welding the filament and the said one support bridge to the lead-in conductors while thus jig-held together to thereby form an intermediate welded assembly, and then jigpositioning the other of said support bridges together with the said welded assembly in predetermined assembled interrelation and welding the said other support bridge to said lead-in conductors.

Il. The method of forming a lamp mount of the type having a segmental filament supported by a support bridge fastened to the lead-in conductors of the mount stem which method comprises, preforming the support bridge and forming hooks on the filament anchor wires thereof, jig-positioning the lament, stem and support bridge together in predetermined assembled interrelation with the filament anchor Wires of the bridge hooked around the bights of theI filament, and then welding the filament and support bridge to the lead-in conductors of the stern-while thus jigheld in predetermined relation thereto.

5. The method of forming a lamp mount of the type having a segmental filament supported by upper and lower support bridges fastened to the lead-in conductors oi the mount stem which method comprises, preforming the said support bridges and forming hooks on the filament anchor wires thereof, `jig-positioning the filament, stem and upper bridge together in predetermined assembled interrelation with the filament anchor wires of the upper bridge hooked around the upper bights of the iilament and with the end connection portions of the lament and the fastening wires of the upper bridge extending across the lead-in conductors of the stem, welding the said filament end connection portions and the bridge fastening Wires to the lead-in conductors while the lament, stem and upper bridge are thus jig-held together in predetermined relation to thereby form an intermediate welded assembly, and then jig-positioning the lower support bridge together with the said Welded assembly in predetermined assembled interrelation with the iilament anchor wires of the lower bridge hooked around the lower bights of the lament and with the fastening wires of the lower bridge eX- tending across the lead-in conductors of the stem, and welding the lower bridge fastening wires to the lead-in conductors while the lower bridge and the said welded assembly are thus jig-held together in predetermined interrelation.

6. Apparatus for welding a support bridge to the lead-in conductors of the stern of an electric incandescent lamp mount having a segmental lament cpmprising individual coiled sections joined together by bights, the support bridge having anchor Wires provided with filament support hooks, said apparatus comprising in combination with a pair of opposed welding electrodes relatively movable toward and away from each other, a jig arranged to hold the `said stem and filament and the said bridge in predetermined assembled inter-relation with weldable portions of the bridge lying across the lead-in conductors, said jig having a spring-actuated member yieldably engageable with the bridge to draw the hooks on the bridge anchor wires tightly intothe bights of the lament, and a support for holding said jig between the said electrodes, said jig being movable on said support laterally of the path of 13 movement of said electrodes and into iixed positions on said support wherein the crossed portions of the bridge and lead-in conductors are selectively located in welding position between the electrodes.

7. Apparatus for welding a support bridge to the lead-in conductors of the stem of an electric incandescent lamp mount comprising a segmental filament having individual coiled sections joined together by bights, the support bridge having anchor wires provided with filament support hooks, said apparatus comprising in combination with a pair of opposed welding electrodes relatively movable toward and away from each other, a jig arranged to hold the said stem and filament and the said bridge in predetermined assembled inter-relation with weldable portions of the bridge lying across the lead-in conductors, said jig having separate guide slots for respectively receiving the anchor wires of the bridge and portions of the stem to thereby position the bridge and the stern in predetermined lateral inter-relation, said jig further having stop means engageable with the stem to position it in a predetermined longitudinal position on the jig, a springactuated member on said jig yieldably engageable with the bridge to draw the hooks on the bridge anchor wires tightly into the bights of the iilament, and a support for holding said jig between the said electrodes, said jig being movable on said support laterally of the path of movement of said electrodes and into xed positions on said support wherein the crossed portions of the bridge and lead-in conductors are selectively located in welding position between the electrodes.

8. Apparatus for welding a filament and a support bridge of an incandescent lamp mount to the lead-in conductors of the stem thereof comprising, in combination with a pair of opposed welding electrodes relatively movable towards and away from each other, a jig arranged to hold the said stem, filament and bridge in predetermined assembled interrelation with weldable portions of the iilamentand the bridge lying across the lead-in conductors, and a support for holding said jig between the said electrodes, said jig being pivoted on said support to swing in a plane transverse to the path of travel of said electrodes for positioning the jig in selective Welding positions wherein the crossed portions of the iilament, bridge and lead-in conductors are located between and aligned with the electrodes.

9. Apparatus for welding to the lead-in conductors of an electric incandescent lamp stem a segmental filament having individual coiled sections joined together by bights and a support bridge having anchor wires provided with filament support h-ooks, said apparatus comprising in combination with a pair of opposed welding electrodes relatively movable towards and away from each other, a jig arranged to hold the said stem, filament and bridge in predetermined assembled interrelation with weldable portions of the filament and the bridge lying across the leadin conductors and with the hooks on the filament anchor wires of the bridge hooked around the bights at one end of the filament body, said jig having separate guide slots for respectively receiving the anchor wires of the bridge and portions of the stem to thereby position the stem Ait? and the bridge in predetermined lateral interrelation, said jig further having separate stop means respectively engageable with the filament and with the iiare on the stem to thereby position the stem and the filament in predetermined longitudinal interrelation, a spring actuated finger yieldably engageable with the bridge to draw the hooks on the bridge anchor wires tightly into the said bights of the filament and hold the filament against its respective stop means, and a support for holding said jig between the said electrodes, said jig being movable on said support laterally of the path of travel of said electrodes for positioning the jig in selective welding positions wherein the crossed portions of the lament, bridge and lead-in conductors are located between and aligned with the electrodes.

10. Apparatus for welding to the lead-in conductors of an electric incandescent lamp stem a segmental filament having individual coiled sections joined together by bights and a support bridge having anchor Wires provided with filament support hooks, said apparatus comprising in combination with a pair of opposed welding electrodes relatively movable towards and away from each other, a jig arranged to hold the said stem, filament and bridge in predetermined assembled interrelation with weldable portions of the iilament and the bridge lying across the leadin conductors and with the hooks on the filament anchor wires of the bridge hooked around the bights at one end of the iilament body, said jig having separate guide slots for respectively receiving the anchor Wires of the bridge and the lead-in conductors and exhaust tube of the stem to thereby position the stem and the bridge in predetermined lateral interrelation, said jig further having separate stop means respectively engageable with the said end of the lament body and with the end of the flare on the stem to thereby position the stem and the filament in predetermined longitudinal interrelation, a spring actuated iinger yieldably engageable with the bridge to draw the hooks on the bridge anchor wires tightly into the siad bights of the lament and hold the filament against its respective stop means, and a support' for holding said jig between the said electrodes, said jig being movable on said support laterally of the path of travel of said electrodes for positioning the jig in selective welding positions wherein the crossed portions of the filament, bridge and lead-in conductors are located between and aligned with the electrodes.

MELVIN L. STONE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTSv Number Name 4 Date 1,792,066 Bowlus Feb. 10, 1931 1,920,630 Conn Aug. 1, 1933 1,981,708 Ragsdale et al Nov. 20, 1934 2,135,288 Koenig Nov. 1, 1938 2,359,434 McNeil Oct. 3, 1944 2,379,135 Ekstedt et al. June 26, 1945 

